Patent GB-263925-A (GB)
Title: Improvements in the spring suspension of vehicles
IPC: B60G11/34
Filed: 1925-10-05
Abstract: 263,925. Carwardine, G. Oct. 5, 1925. Springs, arrangement of.-Relates to suspension arrangements for motor and other vehicles in which in addition to the usual system, a complementary spring system is employed comprising one or more resilient telescopic struts interposed between the sprung and unsprung portions of the vehicle in such a manner that during relative movement of the portions away from a position in which the struts are in a dead. centre position, the action of the complementary system is opposed to that of the usual system. The complementary system is so arranged that the equation to the resultant load-deflection curve is, or approximates to, y= eax, which represents a load-deflection curve for a suspension of constant periodicity, and wherein a is a constant and is the reciprocal of the sub-tangent of the curve. The periodicity of the combined system may be lowered to any desired extent relatively to that of the usual system. Such a combined system for a given usual system may be obtained by giving suitable values to the length of the struts, strength of the complementary spring, and initial compression of such springs. As described, the struts comprise telescoping members 5, 6, Fig. 5, enclosing a compression spring 10, the member 6 being provided with bearing rings 11, 12. A split ring 14 introduced through a slot in the member 5 engages an internal groove in this member and serves to limit the expansion of the spring. The strut is formed with depressions 7 at its ends adapted to engage ballheaded projections 8, 9, Fig. 1, on the sprung and unsprung portions of the vehicle respectively, the strut being maintained in position by its spring. To hold the strut in a compressed condition to facilitate fitting, a stop 16 may be inserted through a slot 17 in the member 5 into an internal groove therein so as to engage the ring 11. Flanged members 22 lined with friction material 3 may be interposed between the depressions 7 and projections 8, 9, and the depressions may be formed with apertures 19 for retaining lubricant, the arrangement being such that frictional resistance comes into play only after the Ranges 22 engage the ends of the strut. Rubber rings may be interposed between the flanges 22 and the struts. Instead of the spring 10, india-rubber or pneumatic springs, or conical helical springs of varying strengths in tandem, may be used. In the arrangement shown in Fig 1, the complementary system comprises a strut arranged between the rear transverse mem. ber 2 of the chassis and the axle casing 3 so that in the normally-loaded static condition of the vehicle the centre line of the strut passes through the centre of the universal joint at the front end of the torque tube 4. In a modification, a pair of horizontal transverse struts are arranged between a central abutment in the axle casing and the side members of the frame. The disposition of the complementary system is such that the rol. ling period is substantially unaffected. In the form shown in Fig. 3, the strut 1 is interposed between a pair of arms 24, 25 pivoted together at 26 and engaging pins 31, 32 on the sprung and unsprung portions of the vehicle.